Anionic vinyl/dicarboxylic acid polymers and uses thereof

ABSTRACT

Biodegradable anionic polymers are disclosed which include recurring polymeric subunits preferably made up of vinylic and dicarboxylic monomers such as vinyl acetate or vinyl alcohol and maleic anhydride, itaconic anhydride or citraconic anhydride, or combinations thereof. Free radical polymerization is used in the synthesis of the polymers, which are then hydrolyzed to replace ester groups with alcohol groups. The polymers may be complexed with ions and/or mixed with fertilizers or seed to yield agriculturally useful compositions. The preferred products of the invention may be applied foliarly, to seeds, to fertilizer, or to the earth adjacent growing plants in order to enhance nutrient uptake by the plants.

RELATED APPLICATION

This is a division of application Ser. No. 09/562,519 filed May 1, 2000,allowed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is broadly concerned with novel anionicsubstantially biodegradable and substantially water soluble polymers andderivatives thereof which have significant utility in agriculturalapplications, especially plant nutrition and related areas. Moreparticularly, the invention is concerned with such polymers, as well asmethods of synthesis and use thereof, wherein the preferred polymershave significant levels of anionic groups. Additionally, the preferredpolymers also include significant levels of alcohol groups. The mostpreferred polymers of the instant invention include recurring polymericsubunits made up of vinylic (e.g., vinyl acetate or vinyl alcohol) anddicarboxylic (e.g., maleic acid, itaconic acid, anhydrides, and otherderivatives thereof) moieties. The polymers may be complexed onto ionsand/or mixed with or coated with phosphate-based fertilizers to provideimproved plant nutrition products.

2. Description of the Prior Art

Lignosulfonates, polyacrylates, polyaspartates and related compoundshave become known to the art of agriculture as materials that facilitatenutrient absorption. All of them suffer from significant disadvantages,which decrease their utility in comparison to the art discussed hereinand limit performance.

Lignosulfonates are a byproduct of paper pulping; they are derived fromhighly variable sources. They are subject to large, unpredictablevariations in color, physical properties, and performance in applicationareas of interest for this invention.

Polyacrylates and polymers containing appreciable levels thereof can beprepared with good control over their composition and performance. Theyare stable to pH variations. However, polyacrylates have just onecarboxylate per repeat unit and they suffer from a very significantlimitation in use, namely that they are not biodegradable. As a result,their utility for addressing the problems remedied by the instantinvention is low.

Polyaspartates are biodegradable, but are very expensive, and are notstable outside a relatively small pH range of about 7 to about 10. Theyusually have very high color, and incorporate amide groups, which causesdifficulties in formulating them. Additionally, polyaspartates have justone carboxylate per repeat unit and are therefore not a part of thepresent invention.

Russian Journal of Applied Chemistry, 24(5):485-489 (1951) teaches thepreparation of maleic anhydride-vinyl acetate copolymers in benzene andacetone with benzoyl peroxide initiators. It further discloses theaddition of above copolymers to water, wherein the polymer graduallyself-hydrolyzes to a complex mixture containing units of maleic acid,vinyl alcohol, vinyl acetate, lactones, free acetic acid, and otherspecies. Deficiencies of this teaching include undesirable presence oflactone, which decreases number of dicarboxylic groups. In addition, nouse for polymers is taught or suggested.

U.S. Pat. Nos. 3,268,491 and 3,887,480 teach preparation of maleicacid-vinyl acetate copolymers in water-based solutions using redox-basedinitiators in a certain pH range. The approaches described in thesepatents are highly problematic. Only redox-type initiators are claimedto be useful. A fixed pH range restricts the practice. Only a narrowrange of copolymers composed exclusively from the monomers of maleicacid and vinyl acetate are taught. The process of U.S. Pat. No.3,268,491 is deemed to be non-commercial by U.S. Pat. No. 3,887,480which described improved processes but uses over 17% by weight of redoxinitiator; such processes are very wasteful, have high environmentalimpact, and are not cost effective.

U.S. Pat. Nos. 5,191,048 and 5,264,510 teach copolymerization of acrylicacid, maleic acid, and vinyl acetate with subsequent hydrolysis by base.Again, several important deficiencies are evident. Among these are theexclusive use of base hydrolysis and preferred embodiments of inventionincorporating monocarboxylic acids. Only terpolymers are disclosed.Furthermore, the intended uses of the compositions are very restrictedand in no way teach, suggest or imply utility of the enumerated andcontemplated compositions for the purposes of the present invention.

It will thus be seen that the prior art fails to disclose or providepolymers which can be synthesized using a variety of monomers andtechniques in order to yield end products which are substantiallybiodegradable, substantially water soluble, and have wide applicabilityfor agricultural uses.

SUMMARY OF THE INVENTION

The present invention overcomes the problems outlined above and providesa new class of anionic polymers having a variety of uses, e.g., forenhancing takeup of nutrient by plants or for mixture with conventionalphosphate-based fertilizers to provide an improved fertilizer product.Advantageously, the polymers are biodegradable, in that they degrade toenvironmentally innocuous compounds within a relatively short time (upto about 1 year) after being in intimate contact with soil. That is tosay that the degradation products are compounds such as CO₂ and H₂O orthe degradation products are absorbed as food or nutrients by soilmicroorganisms and plants. Similarly, derivatives of the polymers and/orsalts of the polymers (e.g. ammonium salt forms of the polymer) alsodegrade within a relatively short time, during which significantfractions of the weight of the polymer are believed to be metabolized bysoil organisms.

Broadly speaking, the anionic polymers of the invention includerecurring polymeric subunits made up of at least two different moietiesindividually and respectively taken from the group consisting of whathave been denominated for ease of reference as A, B and C moieties.Thus, exemplary polymeric subunits may be AB, BA, AC, CA, ABC, BAC, CAB,or any other combination of A moieties with B and C moieties. Moreover,in a given polymer different polymeric subunits may include differenttypes or forms of moieties, e.g., in an AB recurring polymeric unitpolymer, the B moiety may be different in different units.

In detail, moiety A is of the general formula

moiety B is of the general formula

and moiety C is of the general formula

wherein R₁, R₂ and R₇ are individually and respectively selected fromthe group consisting of H, OH, C₁-C₃₀ straight, branched chain andcyclic alkyl or aryl groups, C₁-C₃₀ straight, branched chain and cyclicalkyl or aryl C₁-C₃₀ based ester groups (formate (C₀), acetate (C₁),propionate (C₂), butyrate (C₃), etc. up to C₃₀), R′CO₂ groups, and OR′groups, wherein R′ is selected from the group consisting of C₁-C₃₀straight, branched chain and cyclic alkyl or aryl groups; R₃ and R₄ areindividually and respectively selected from the group consisting of H,C₁-C₃₀ straight, branched chain and cyclic alkyl or aryl groups; R₅, R₆,R₁₀ and R₁₁ are individually and respectively selected from the groupconsisting of H, the alkali metals, NH₄ and the C₁-C₄ alkyl ammoniumgroups, Y is selected from the group consisting of Fe, Mn, Mg, Zn, Cu,Ni, V, Cr, Si, B, Co, Mo, and Ca; R₈ and R₉ are individually andrespectively selected from the group consisting of nothing (i.e., thegroups are non-existent), CH₂, C₂H₄, and C₃H₆, at least one of said R₁,R₂, R₃ and R₄ is OH where said polymeric subunits are made up of A and Bmoieties, at least one of said R₁, R₂ and R₇ is OH where said polymericsubunits are made up of A and C moieties, and at least one of said R₁,R₂, R₃, R₄ and R₇ is OH where said polymeric subunits are made up of A,B and C moieties.

As can be appreciated, the polymers of the invention can have differentsequences of recurring polymeric subunits as defined above (for example,a polymer comprising A, B and C subunits may include the one form of Amoiety, all three forms of B moiety and all three forms of C moiety). Inthe case of the polymer made up of A and B moieties, R₁-R₄ arerespectively and individually selected from the group consisting of H,OH and C₁-C₄ straight and branched chain alkyl groups, R₅ and R₆ areindividually and respectively selected from the group consisting of thealkali metals.

The most preferred polymers of the invention are made up of recurringpolymeric subunits formed of A and B moieties, wherein R₅ and R₆ areindividually and respectively selected from the group consisting of H,Na, K, and NH₄ and specifically wherein R₁, R₃ and R₄ are each H, R₂ isOH, and R₅ and R₆ are individually and respectively selected from thegroup consisting of H, Na, K, and NH₄ depending upon the specificapplication desired for the polymer. These preferred polymers have thegeneralized formula

wherein R₅ and R₆ are individually and respectively selected from thegroup consisting of H, the alkali metals, NH₄ and C₁-C₄ alkyl ammoniumgroups (and most preferably, H, Na, K and NH₄ depending upon theapplication), and n ranges from about 1-10000 and more preferably fromabout 1-5000.

For purposes of the present invention, it is preferred to usedicarboxylic acids, precursors and derivatives thereof for the practiceof the invention. For example, terpolymers containing mono anddicarboxylic acids with vinyl esters and vinyl alcohol are contemplated,however, polymers incorporating dicarboxylic acids were unexpectedlyfound to be significantly more useful for the purposes of thisinvention. This finding was in contrast to the conventional teachingsthat mixtures of mono and dicarboxylates were superior in applicationspreviously suggested for mono-carboxylate polymers. Thus, the use ofdicarboxylic acid derived polymers for agricultural applications isunprecedented and produced unexpected results. It is understood thatwhen dicarboxylic acids are mentioned herein, various precursors andderivatives of such are contemplated and well within the scope of thepresent invention. Put another way, copolymers of the present inventionare made up of monomers bearing at least two carboxylic groups orprecursors and/or derivatives thereof. The polymers of the invention mayhave a wide variety of molecular weights, ranging for example from500-5,000,000, more preferably from about 1,500-20,000, dependingchiefly upon the desired end use.

In many applications, and especially for agricultural uses, the polymersof the invention may be mixed with or complexed with a metal ornon-metal ion, and especially ions selected from the group consisting ofFe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V, Cr, Si, B, and Ca. Alternatively,polymers containing, mixed with or complexed with such elements may beformulated using a wide variety of methods that are well known in theart of fertilizer formation. Examples of such alternative methodsinclude, forming an aqueous solution containing molybdate and the sodiumsalt of polymers in accordance with the invention, forming an aqueoussolution which contains a zinc complex of polymers in accordance withthe present invention and sodium molybdate, and combinations of suchmethods. In these examples, the presence of the polymer in soil adjacentgrowing plants would be expected to enhance the availability of theseelements to these growing plants. In the case of Si and B, the elementwould merely be mixed with the polymer rather than having a coordinatemetal complex formation. However, in these cases, the availability ofthese ions would be increased for uptake by growing plants and will betermed “complexed” for purposes of this application.

The polymers hereof (with or without complexed ions) may be useddirectly as plant growth enhancers. For example, such polymers may bedispersed in a liquid aqueous medium and applied foliarly to plantleaves or applied to the earth adjacent growing plants. It has beenfound that the polymers increase the plant's uptake of bothpolymer-borne metal nutrients and ambient non-polymer nutrients found inadjacent soil. In such uses, plant growth-enhancing amounts ofcompositions comprising the above-defined polymers are employed, eitherin liquid dispersions or in dried, granular form. Thus, application ofpolymer alone results in improved plant growth characteristics,presumably by increasing the availability of naturally occurring ambientnutrients. Typically, the polymers are applied at a level of from about0.001 to about 100 lbs. polymer per acre of growing plants, and morepreferably from about 0.005 to about 50 lbs. polymer per acre, and stillmore preferably from about 0.01 to about 2 lbs.

In other preferred uses, the polymers may be used to form compositeproducts where the polymers are in intimate contact with fertilizerproducts including but not limited to phosphate-based fertilizers suchas monoammonium phosphate (MAP), diammonium phosphate (DAP), any one ofa number of well known N—P—K fertilizer products, and/or fertilizerscontaining nitrogen materials such as ammonia (anhydrous or aqueous),ammonium nitrate, ammonium sulfate, urea, ammonium phosphates, sodiumnitrate, calcium nitrate, potassium nitrate, nitrate of soda, ureaformaldehyde, metal (e.g. zinc, iron) ammonium phosphates; phosphorousmaterials such as calcium phosphates (normal phosphate and superphosphate), ammonium phosphate, ammoniated super phosphate, phosphoricacid, superphosphoric acid, basic slag, rock phosphate, colloidalphosphate, bone phosphate; potassium materials such as potassiumchloride, potassium sulfate, potassium nitrate, potassium phosphate,potassium hydroxide, potassium carbonate; calcium materials, such ascalcium sulfate, calcium carbonate, calcium nitrate; magnesiummaterials, such as magnesium carbonate, magnesium oxide, magnesiumsulfate, magnesium hydroxide; sulfur materials such as ammonium sulfate,sulfates of other fertilizers discussed herein, ammonium thiosulfate,elemental sulfur (either alone or included with or coated on otherfertilizers); micronutrients such as Zn, Mn, Cu, Fe, and othermicronutrients discussed herein; oxides, sulfates, chlorides, andchelates of such micronutrients (e.g., zinc oxide, zinc sulfate and zincchloride); such chelates sequestered onto other carriers such as EDTA;boron materials such as boric acid, sodium borate or calcium borate; andmolybdenum materials such as sodium molybdate. As known in the art,these fertilizer products can exist as dry powders/granules or as watersolutions.

In such contexts, the polymers may be co-ground with the fertilizerproducts, applied as a surface coating to the fertilizer products, orotherwise thoroughly mixed with the fertilizer products. Preferably, insuch combined fertilizer/polymer compositions, the fertilizer is in theform of particles having an average diameter of from about powder size(less than 0.001 cm) to about 10 cm, more preferably from about 0.1 cmto about 2 cm, and still more preferably from about 0.15 cm to about 0.3cm. The polymer is present in such combined products at a level of fromabout 0.001 g to about 20 g polymer per 100 g phosphate-basedfertilizer, more preferably from about 0.1 g to about 10 g polymer per100 g phosphate-based fertilizer, and still more preferably from about0.5 g to about 2 g polymer per 100 g phosphate-based fertilizer. Again,the polymeric fraction of such combined products may include thepolymers defined above, or such polymers complexed with theaforementioned ions. In the case of the combined fertilizer/polymerproducts, the combined product is applied at a level so that the polymerfraction is applied at a level of from about 0.001 to about 20 lbs.polymer per acre of growing plants, more preferably from about 0.01 toabout 10 lbs polymer per acre of growing plants, and still morepreferably from about 0.5 to about 2 lbs polymer per acre of growingplants. The combined products can likewise be applied as liquiddispersions or as dry granulated products, at the discretion of theuser. When polymers in accordance with the present invention are used asa coating, the polymer comprises at least about 0.01% by weight of thecoated fertilizer product, more preferably the polymer comprises atleast about 5% by weight of the coated fertilizer product, and mostpreferably comprises at least about 10% by weight of the coatedfertilizer product.

Additionally, use of polymers in accordance with the present inventionincreases the availability of phosphorus and other common fertilizeringredients and decreases nitrogen volitilization, thereby renderingambient levels of such plant nutrient available for uptake by growingplants. In such cases, the polymer can be applied as a coating tofertilizer products prior to their introduction into the soil. In turn,plants grown in soil containing such polymers exhibit enhanced growthcharacteristics.

Another alternative use of polymers in accordance with the presentinvention includes using the polymer as a seed coating. In such cases,the polymer comprises at least about 0.01% by weight of the coated seed,and more preferably comprises at least about 5% by weight of the coatedseed, and still more preferably comprises at least about 10% by weightof the coated seed.

In general, the polymers of the invention are made by free radicalpolymerization serving to convert selected monomers into the desiredpolymers with recurring polymeric subunits. Such polymers may be furthermodified to impart particular structures and/or properties. A variety oftechniques can be used for generating free radicals, such as addition ofperoxides, hydroperoxides, azo initiators, percarbonate, per-acid,charge transfer complexes, irradiation (e.g., UV, electron beam, X-ray,gamma-radiation and other ionizing radiation types), and combinations ofthese techniques. Of course, an extensive variety of methods andtechniques are well known in the art of polymer chemistry for initiatingfree-radical polymerizations. Those enumerated herein are but some ofthe more frequently used methods and techniques. Any suitable techniquefor performing free-radical polymerization is likely to be useful forthe purposes of practicing the present invention.

The polymerization reactions are carried out in a compatible solventsystem, namely a system which does not unduly interfere with the desiredpolymerization, using essentially any desired monomer concentrations. Anumber of suitable aqueous or non-aqueous solvent systems can beemployed, such as ketones, alcohols, esters, ethers, aromatic solvents,water and mixtures thereof. Water alone and the lower (C₁-C₄) ketonesand alcohols are especially preferred, and these may be mixed with waterif desired. In most instances, the polymerization reactions are carriedout with the substantial exclusion of oxygen, and most usually under aninert gas such as nitrogen or argon. There is no particular criticalityin the type of equipment used in the synthesis of the polymers, i.e.,stirred tank reactors, continuous stirred tank reactors, plug flowreactors, tube reactors and any combination of the foregoing arranged inseries may be employed. A wide range of suitable reaction arrangementsare well known to the art of polymerization.

In general, the initial polymerization step is carried out at atemperature of from about 0° C. to about 120° C. (more preferably fromabout 30° C. to about 95° C. for a period of from about 0.25 hours toabout 24 hours and even more preferably from about 0.25 hours to about 5hours. Usually, the reaction is carried out with continuous stirring.

After the initial polymerization, the products are recovered andhydrolyzed so as to replace at least certain of the ester-containinggroups on the polymer with alcohol groups, thereby providing thepolymers defined previously. Generally, the hydrolyzing step involvesthe addition of an acid or base to the polymerized product in thepresence of water. Polymers comprising monomers with vinyl ester groups(polymers formed at least in part from A moieties) need to havesufficient base added to neutralize all of the carboxylic acid groupsand form a substantial number of alcohol groups from the precursor vinylester groups. Thereafter, the completed polymer may be recovered as aliquid dispersion or dried to a solid form. It is important to note thatboth acid and base hydrolysis are useful in practicing the presentinvention so that under appropriate conditions, sufficient acid must beadded in order to form a substantial number of alcohol groups.Additionally, in many cases it is preferred to react the hydrolyzedpolymer with an ion such as Fe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V, Cr, andCa to form a coordinate metal complex. Techniques for makingmetal-containing polymer compounds are well known to those skilled inthe art. In some of these techniques, a metal's oxide, hydroxide,carbonate, salt, or other similar compound may be reacted with thepolymer in acid form. These techniques also include reacting a finelydivided free metal with a solution of an acid form of a polymerdescribed or suggested herein. Additionally, the structures of complexesor salts of polymers with metals in general, and transition metals inparticular, can be highly variable and difficult to precisely define.Thus, the depictions used herein are for illustrative purposes only andit is contemplated that desired metals or mixtures of such are bonded tothe polymer backbone by chemical bonds. Alternatively, the metal may bebonded to other atoms in addition to those shown. For example, in thecase of the structure shown herein for the second reactant, there may beadditional atoms or functional groups bonded to the Y. These atomsinclude, but are not limited to, oxygen, sulfur, halogens, etc. andpotential functional groups include (but are not limited to) sulfate,hydroxide, etc. It is understood by those skilled in the art ofcoordination compound chemistry that a broad range of structures may beformed depending upon the preparation protocol, the identity of themetal, the metal's oxidation state, the starting materials, etc.Alternatively, acid hydrolysis may be performed followed by a reactionto form a complex with a previously enumerated metal. In yet anotheralternative method, the polymer may be isolated and subsequentlyformulated in such a way that the hydrolysis reaction occurs in situ, inthe soil or during mixture with a fertilizing composition. In thisalternative method, unhydrolyzed polymer is added to soil or fertilizercompositions of appropriately low or high pH such that when contacted bywater, a microenvironment of low or high pH is produced. It is withinthis microenvironment that hydrolysis occurs and alcohol groups areformed. In the case of Si and B ions, the polymer is merely mixed withthese ions and does not form a coordinate complex. However, theavailability of these ions to growing plants is increased.

In more detail, the preferred method for polymer synthesis comprises thesteps of providing a reaction mixture comprising at least two differentreactants selected from the group consisting of first, second, and thirdreactants. The first reactant is of the general formula

the second reactant is of the general formula

and the third reactant is of the general formula

With reference to the above formulae, R₁, R₂ and R₇ are individually andrespectively selected from the group consisting of H, OH, C₁-C₃₀straight, branched chain and cyclic alkyl or aryl groups, C₁-C₃₀straight, branched chain and cyclic alkyl or aryl C₁-C₃₀ based estergroups (formate (C₀), acetate (C₁), propionate (C₂), butyrate (C₃), etc.up to C₃₀), R′CO₂ groups, and OR′ groups, wherein R′ is selected fromthe group consisting of C₁-C₃₀ straight, branched chain and cyclic alkylor aryl groups; R₃ and R₄ are individually and respectively selectedfrom the group consisting of H, C₁-C₃₀ straight, branched chain andcyclic alkyl or aryl groups; R₅, R₆, R₁₀ and R₁₁ are individually andrespectively selected from the group consisting of H, the alkali metals,NH₄ and the C₁-C₄ alkyl ammonium groups, Y is selected from the groupconsisting of Fe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V, Cr, Si, B, and Ca; R₈and R₉ are individually and respectively selected from the groupconsisting of nothing (i.e., the groups are non-existent), CH₂, C₂H₄,and C₃H₆, at least one of said R₁, R₂, R₃ and R₄ is OH where saidpolymeric subunits are made up of A and B moieties, at least one of saidR₁, R₂ and R₇ is OH where said polymeric subunits are made up of A and Cmoieties, and at least one of said R₁, R₂, R₃, R₄ and R₇ is OH wheresaid polymeric subunits are made up of A, B and C moieties.

Selected monomers and reactants are dispersed in a suitable solventsystem and placed in a reactor. The polymerization reaction is thencarried out to obtain an initial polymerized product having thedescribed recurring polymeric subunits. Thereupon, the initial polymerproduct is hydrolyzed to the alcohol form. Put another away, the generalreaction proceeds by dissolving monomers (e.g., maleic anhydride andvinyl acetate) in a solvent (e.g., acetone). The amount of monomersincorporated can be either equimolar or non-equimolar. A free radicalinitiator is then introduced and copolymerization takes place insolution. After the reaction is complete and substantially all monomerhas been reacted, the resulting solution is a maleic anhydride-vinylacetate copolymer. Of course, if all monomers have not undergonepolymerization, the resulting solution will contain a small portion ofmonomers which do not affect later use of the polymer. The solution isconcentrated and subjected to hydrolysis (either in situ or byperforming a hydrolysis reaction during manufacture) with a sufficientamount of base (e.g., NaOH) in the presence of water. This baseneutralizes a substantial majority of the carboxylic acid groups andconverts a substantial majority of the polymer's acetate groups intoalcohol groups. The anhydride groups are converted to carboxylic acidsodium salt groups arranged in groups of two on the backbone of thepolymer. The resulting copolymer is then isolated by conventionalmethods such as precipitation.

Again, it is important to note that the aforementioned methods andprocedures are merely preferred methods of practicing the presentinvention and those skilled in the art understand that a large number ofvariations and broadly analogous procedures can be carried out using theteachings contained herein. For example, acid hydrolysis can also beused followed optionally by formation of various derivatives or thehydrolysis may be carried out naturally in soil under sufficientmoisture and pH conditions. The acid hydrolysis isolates the polymers ofthe present invention in a substantially acid form which renders themhighly versatile and useful. These polymers may be used as is (in theacid form) or further reacted with various materials to make saltsand/or complexes. Furthermore, complexes or salts with various metalsmay be formed by reacting the acid form with various oxides, hydroxides,carbonates, and free metals under suitable conditions. Such reactionsare well known in the art and include (but are not limited to) varioustechniques of reagent mixing, monomer and/or solvent feed, etc. Onepossible technique would be gradual or stepwise addition of an initiatorto a reaction in progress. Other potential techniques include theaddition of chain transfer agents, free radical initiator activators,molecular weight moderators/control agents, use of multiple initiators,initiator quenchers, inhibitors, etc. Of course, this list is notcomprehensive but merely serves to demonstrate that there are a widevariety of techniques available to those skilled in the art and that allsuch techniques are embraced by the present invention.

Another alternative method involves taking an aqueous solution of, forexample, caustic and stirring it in a suitable container. Next, anacetone reaction mixture containing, for example, acetone and acopolymer of maleic anhydridc with vinyl acetate is added to the causticsolution. Throughout this addition, the polymer going into the causticsolution will experience a high pH and have the acetate groupshydrolyzed to the alcohol form. In acid-base titrations such as this, atthe point where one reagent is just exhausted, a very sharp pH changeusually takes place with minimal addition of the second reagent.Therefore, in this reaction, just enough acetone-polymer reactionsolution is added to bring the apparent pH of the now final polymerproduct-acetone-water mixture to about 7. At this time, the mixture issubjected to reduced pressure distillation to remove acetone. The resultis an aqueous solution at a neutral pH that contains the desiredpolymer. From this solution, it may be isolated by a variety of ways,including but not limited to precipitation, spray drying, simple drying,and etc. The only side effect of a reaction of this type is that a smallfraction of the polymer is going to contain acetate groups which are nothydrolyzed to alcohol.

The foregoing description is useful in instances where polymers inaccordance with the present invention, upon dissolution in water, give asolution that is alkaline. In many cases, this alkalinity is not aproblem as the solution pH can be adjusted to neutral or acidic with asuitable mineral or organic acid. However, the formulation of thispowder into some liquid formulations containing metals is problematic.High-pH solutions of metal salts tend to form insoluble metal hydroxidesthat precipitate and/or exhibit other behaviors that are undesirablefrom the point of view of formulation ease and convenience, as well asnutrient availability. One way to remedy this problem, other than asdescribed in the preceding paragraph, is to add a mineral or organicacid to the aqueous solution of polymer salt in order to bring the pHclose to neutral.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following examples set forth techniques for the synthesis ofpolymers in accordance with the invention, and various uses thereof. Itis to be understood that these examples are provided by way ofillustration only and nothing therein should be taken as a limitationupon the overall scope of the invention.

EXAMPLE 1

Acetone (111 ml), maleic anhydride (20 g), vinyl acetate monomer (19ml), and the radical source initiator di-tertbutyl peroxide (2.4 ml)were stirred together under inert gas (such as nitrogen or argon) in areactor. The reactor provided included a suitably sized glass sphericalflask equipped with a magnetic stirrer, an inert gas inlet, a contentstemperature measurement device in contact with the contents of theflask, and a removable reflux condenser. This combination of materialswas heated in a hot water bath with stirring at an internal temperatureof about 70° C. for five hours. At that point, the contents of the flaskwere evaporated (by removing the condenser with continued heating) to athick oil. and 100 ml of water was added. Then, 18 g of granular sodiumhydroxide (NaOH) was added to the above dispersion. The resultingmixture was heated again to about 100° C. and allowed to reflux forabout two hours. The mixture was then allowed to evaporate by removal ofthe condenser to a slightly viscous mass. This mass was precipitated byadding the evaporated mixture to about 0.5 liters of ethanol whilestirring was continued. The solids were recovered and then dried. Theresulting product was a white-colored powder. These reactions proceededas follows:

EXAMPLE 2

This reaction was carried out similarly to that of Example 1. However,in this case the following quantities of ingredients were used: acetone(50 ml), maleic anhydride (44 g), vinyl acetate monomer (42 ml), anddi-tertbutyl peroxide (8.3 ml). This mixture was heated in a hot waterbath with stirring at an internal temperature of about 70° C. for fivehours. The contents of the reactor flask were then evaporated to a thickoil and 100 ml of water was added. Next, 57 g granular NaOH was added.This mixture was heated again to about 100° C. and allowed to reflux forabout one hour. After refluxing, the mixture evaporated to a slightlyviscous mass. This mass was precipitated by adding it, with stirring to0.9 liters of ethanol. The solids were then recovered and dried. Theresulting product was a tan-colored powder.

EXAMPLE 3

This reaction was also carried out as in Example 1. However, thefollowing quantities of ingredients were used: acetone (273.0 ml),maleic anhydride (49 g), vinyl acetate monomer (46 ml), and di-tertbutylperoxide (5.9 ml). This mixture was heated in a hot water bath withstirring at an internal temperature of about 70° C. for five hours. Thecontents of the flask were then evaporated into a thick oil (once againby removing the condenser), and 250 ml of water was added. Following thewater addition, 63 g of granular NaOH was added. The resulting mixturewas heated to about 100° C. again, and allowed to reflux for about onehour. This mixture was then evaporated to a slightly viscous mass. Themass was precipitated with stirring into about 2 liters of ethanol.Solids were recovered and dried and the product was a very bright whitepowder.

EXAMPLE 4

In this example, copper was complexed with the polymer isolated inExample 1. Five grams of the Example 1 polymer was mixed with 50 g (dryweight) of ion exchange resin (strong acid macro reticular, 4.9 meq/gramdry) which had been soaked in water until the mixture was fluid. Theacid form of the polymer was then washed out with several aliquots ofwater. The resultant water-polymer mixture was then mixed with 6 g ofCuSO₄ pentahydrate. The aqueous solution containing the copper complexwas then evaporated to dryness and the material was collected.

EXAMPLE 5

One gram of the polymer prepared and isolated in Example 1 was dissolvedinto 20 ml of room temperature water. 1.3 g sodium bisulfate was addedto this dispersion with stirring. While stirring was continued, 0.5 g offerric sulfate (Fe₂(SO₄)₃) tetrahydrate was added slowly with stirring.This product was isolated by evaporating the water from the solution todryness. Thereafter, the isolated dry material was collected. Theresultant product was an iron complex of the polymer of Example 1.

EXAMPLE 6

In this example, 1 g of the polymer prepared and isolated in Example 1was added to 20 ml of room temperature water. Sulfuric acid (98%) wasadded to the dispersion with stirring, until the pH dropped to about 2.1.5 g of manganese dichloride tetrahydrate was added slowly to thedispersion with vigorous stirring. The material (a manganese complex ofthe Example 1 polymer) was then evaporated to dryness and the materialwas collected.

EXAMPLE 7

Five grams of the polymer prepared and isolated in Example 1 wasdissolved in 100 ml of water. Sulfuric acid (98%) was added until the pHdropped to about 2.7 g of zinc sulfate heptahydrate was added slowlywith vigorous stirring to the dispersion. The resulting solution had theproduct (a zinc complex of the Example 1 polymer) isolated byevaporating the water to dryness and was collected thereafter.

EXAMPLE 8

Water (30 g), and maleic anhydride (20 g) is put into the reactor withstirring under inert gas, such as nitrogen or argon. During this time,the anhydride is converted to the acid form. Di-tertbutyl peroxide (2.4ml) is added to the flask. The resulting mixture is heated and refluxeduntil the reflux head temperature gradually rises to about 100° C. Atthis point, vinyl acetate monomer (19 ml) is gradually added to thereaction at about the same rate that it is consumed. The reaction iscarried out until substantially all monomer is consumed. The product ofthis synthesis is then hydrolyzed as in Example 1. This exampledemonstrates that the preferred polymerization may be carried out in anaqueous medium.

EXAMPLE 9

The product of the reaction described in Example 8 is refluxed overnightat about 100° C. and then subjected to a short-path distillation underinert atmosphere in order to remove the acetic acid hydrolysis product.Due to the high temperature and high product concentration, lactoneformation is minimized, and the fraction of dicarboxylic acid functionalgroups that are available is maximized. The desired product is isolatedby spray-drying the aqueous solution to give a white amorphous powder.

EXAMPLE 10

This example is similar to that described in Example 8; however, wateris replaced with a 1:1 (w/w) mixture of water and ethanol. 20 g ofmaleic anhydride is added to this mixture. Next, di-tertbutyl peroxide(2.4 ml) is added to the reactor and the resulting mixture is heated toreflux until the reflux head temperature rises to about 100° C. Vinylacetate monomer is then gradually added to the reaction at about thesame rate it is consumed. Once again, 19 ml of vinyl acetate monomer isused. The reaction is carried out until substantially all of the monomeris consumed. The resulting product is then refluxed overnight andsubjected to a short-path distillation under inert atmosphere in orderto remove the acetic acid hydrolysis product. Once again, due to thehigh temperature and high product concentration, lactone formation isminimized and the fraction of dicarboxylic acid functional groups ismaximized. The desired product is then isolated by spray-drying theaqueous solution to give a white amorphous powder.

EXAMPLE 11

This Example demonstrates that the polymerization may be carried outusing UV free radical initiation instead of peroxide. Water (30 g) andmaleic anhydride (20 g) is mixed in the reactor under inert gas. A 10watt lamp emitting UV radiation at the 190-210 nm wavelength range isimmersed in the reaction vessel. The mixture is heated to reflux untilthe reflux head temperature gradually rises to about 100° C., at whichpoint 19 ml of vinyl acetate monomer is gradually added to the reactionat about the same rate as it is consumed. The reaction is carried outuntil substantially all of the monomer is consumed. Once synthesis(copolymerization) is substantially complete, the resultant product ishydrolyzed as in Example 1.

EXAMPLE 12

In this example, polymerization is carried out using UV free radicalinitiation in a mixture of organic solvent and water. The experiment iscarried out as in Example 11, but water is replaced with a 1:1 (w/w)mixture of water and ethanol. The isolation and hydrolysis proceduresare substantially the same as those used in Examples 8 and 9.

EXAMPLE 13

In this example, the procedure of Example 8 is carried out except that 1ml of hydrogen peroxide (30% w/w) is used instead of di-tertbutylperoxide.

EXAMPLE 14

This example demonstrates acid hydrolysis in an aqueous medium. To theproduct of the reaction described in Example 8, 0.2 g 98% of sulfuricacid is added and the mixture is refluxed overnight at about 100° C.Next, the mixture is subjected to a short-path distillation under inertgas to remove the acetic acid hydrolysis product. Due to the acidity,high temperature and high product concentration, lactone formation isminimized, and the fraction of dicarboxylic acid functional groups ismaximized. The product is isolated by spray drying the aqueous solutionto give a white amorphous powder.

EXAMPLE 15

An aqueous solution composed of 40 g water, 11.6 g maleic acid and 8.1 gzinc oxide is formed. The oxide slowly reacts and dissolves to give zincmaleate derivative solution. This is used as a monomer source in apolymerization such as that described in Example 8 where equimolaramounts of maleate and vinyl acetate were used. After that, a hydrolysisis performed using the procedures described in Example 14. The reactionproceeded as follows:

EXAMPLE 16

An aqueous solution composed of 40 g water, 11.6 g maleic acid, and 11.5g manganese carbonate is prepared. The carbonate slowly reacts anddissolves to give manganese maleate derivative solution. This manganesemaleate solution is used as a monomer source in a polymerization such asthat described in Example 8, wherein equimolar amounts of maleate andvinyl acetate were used. After that, a hydrolysis is performed using theprocedures described in Example 14. The reaction proceeded as follows:

EXAMPLE 17

An aqueous solution composed of 40 g water, 11 g maleic acid, and 5.6 gvery fine iron dust is formed. The metal slowly reacts and dissolves togive iron maleate derivative solution. This solution is used as amonomer source in a polymerization reaction such as that described inExample 8, wherein equimolar amounts of maleate and vinyl acetate wereused. After that, a hydrolysis is performed using the proceduresdescribed in Example 14. This reaction proceeded as follows:

EXAMPLE 18

A continuous reactor is provided including an in-line motionless tubemixer, pumps, thermostatted tubes, and associated valves, fittings, andcontrols. Maleic anhydride (50% w/w in acetone), vinyl acetate anddi-tertbutyl peroxide are pumped into the in-line tube mixer and theninto the thermostatted tube. The mixture's residence time in the tube isabout 3 hours. The tube temperature is about 70° C. The flow rates are:maleic anhydride solution—100 g/min; vinyl acetate—43 g/min, anddi-tertbutyl peroxide—3 g/min. Hydrolysis is performed using theprocedures described in Example 14.

EXAMPLE 19

Aqueous dispersions containing 10, 50 and 100 ppm of the copper,manganese and zinc copolymers formed in Examples 4, 6 and 7 were appliedto the foliage of plum, maple and sweetgum trees, respectively, in orderto obtain substantially uniform foliage coverage. Prior to thisapplication, the trees visually exhibited characteristic deficiencysymptoms for each of the three micronutrients. This treatment alleviatedthe visual symptoms of the micronutrient deficiency in about 7-10 days.

EXAMPLE 20

Bluegrass was treated with aqueous dispersions of the iron copolymerfrom Example 5 (20, 50 and 100 ppm concentrations of iron copolymer) andcompared to an untreated control which received no iron copolymer. Thesefoliar iron treatments were applied at three different times aspretreatments before bluegrass was harvested. Photos of the plants weretaken two weeks after the last treatment. The results (Table 1) clearlyshow that the bluegrass responded to the iron copolymer application. Thetotal harvest weights for each of the three iron copolymer bluegrasstest groups were at least twice that of the control bluegrass. As theamount of copolymer applied increased, harvest weight also increased.

TABLE 1 Bluegrass Response to Varying Concentrations of Fe CopolymerHarvest Wts (g) Fe Copolymer Concentration Applied Harvest 0 ppm 25 ppm50 ppm 100 ppm 1 0.3 1.6 1.8 2.1 2 1.8 2.9 2.1 2.0 3 1.4 2.5 3.6 3.9Total 3.5 7.0 7.5 8.0

EXAMPLE 21

In this example, the effect of iron copolymer treatment on Lisintus wasdetermined. The iron copolymer of Example 5 was used for thisexperiment. The first control group of plants received no iron copolymertreatment, the second group was foliarly treated with an aqueousdispersion containing 50 ppm of the iron copolymer on three differentoccasions before harvest, and the third group was similarly treated withan aqueous dispersion containing 100 ppm iron copolymer three timesbefore harvest. The Lisintus was harvested and analyzed (by digestionfollowed by atomic absorption spectroscopy) for iron concentration, andby SPAD meter to determine photosynthetically active chlorophyl levels.The results of this experiment are given in Table 2 which shows thatapplication of iron copolymer resulted in a higher iron concentration inthe Lisintus leaves. However, the amount of iron copolymer applied tothe Lisintus did not have an appreciable effect on ultimate ironconcentration (i.e. SPAD meter readings between Lisintus treated with 50ppm iron copolymer and 100 ppm iron copolymer did not differsignificantly). Therefore, the most efficient treatment may occur atlevels below 50 ppm.

TABLE 2 Iron Concentration and SPAD Meter Readings of Lisintus LeavesTreated with Foliar Applications of Iron Copolymer Treatment Fe Uptake(ppm) SPAD Meter Readings Control 146 29.5  50 ppm 276 63.7 100 ppm 30964.1

EXAMPLE 22

In this experiment, different amounts of the copolymer formed in Example1 were used in conjunction with phosphate fertilizer in soil, in orderto test the effect of using the polymer with the fertilizer. Inparticular, the test was conducted on ryegrass grown in growth bags. Thegrowth bags contained soil, water and a conventional, commerciallyavailable 8-14-9 N PK liquid fertilizer. One growth bag (the control)had no copolymer added. One bag labeled 0.5× was treated with afertilizer mixture containing 25 ppm of the copolymer (the copolymer wasadded to the liquid fertilizer prior to addition thereof to the growthbags). The bag labeled 1× was treated with a liquid fertilizer mixturecontaining 50 ppm of copolymer. The fertilizer solution in the growthbags were replenished uniformly on an as-needed basis. After the grasswas harvested, it was dried and weighed. Results of this experiment aregiven in Table 3 which shows no response to the 0.5× copolymerapplication. The 1× copolymer application resulted in a 25% increase indry weight.

TABLE 3 Effects of Copolymer with Liquid Fertilizer on Resulting PlantGrowth Treatment Average Shoot Weight  1X Copolymer and LiquidFertilizer 33.0 .5X Copolymer and Liquid Fertilizer 25.0 Control-LiquidFertilizer Only 24.9

EXAMPLE 23

In this test, the copolymer from Example 1 was tested with phosphatefertilizers in high phosphate-fixing soils in corn growth tests. Thetest was designed to determine the effect of the copolymer on the plantavailability of phosphate based fertilizer in the soil. For thisexperiment, monoammonium phosphate (MAP) was tested although it isunderstood that similar results would occur with any phosphate basedfertilizer.

Two soils were utilized in the study, an acid soil (pH 4.5-4.7) fromSedgewick County, KS and a calcareous soil (pH 8.0-8.3) from thevicinity of Tribune, Kans. The acid soil is high in available P butowing to the high exchangeable Al and Fe content of the soil, Pavailability is limited. The calcareous soil was lower in available P.

Containers (flats) approximately 75 cm×40 cm were used for the study.These flats held approximately 8 kg of soil filled to a depth ofapproximately of 7.5 cm, and allows planting in rows with band placementof the fertilizer material, beside the row or in seed contact ifdesired. Multiple rows within each container were used as replications.The containers served as individual treatment for each crop and wererotated to eliminate any possible variables of light and/or temperature.

Corn was used as the test crop. The seeds were planted in rows, thinnedto a constant population per row. Only a single variety of corn was usedfor each crop. Corn was taken to approximately the 6-leaf stage beforethe whole plant was harvested for dry weight and plant compositionanalysis. In the corn test, four plants per row per replication wereused, thinned back from ten plants.

Conventional Cargill MAP fertilizer was used, with the fertilizer beingcoated with the copolymer product of Example 1 at rates of 1 gcopolymer/100 g MAP (P1×) and 2 g copolymer/100 g MAP (P2×). The MAPparticles were sized prior to copolymer application to insure that theindividual particles were of approximately the same size. In allinstances, a single rate of application of 20 ppm phosphorus calculatedas P₂O₅ was employed. In addition, a no-phosphorus control was alsoincluded in the study for each crop on each soil. Other nutrients weresupplied at constant rates.

The fertilizer-copolymer MAP product was applied in a banded fashionwith a constant number of phosphate material particles utilized per row(63 particles per each 10 inch row section). This procedure placed theexperimental products close to the rows for maximum availability in thephosphate-fixing conditions, and allowed comparison of the effect of thecopolymer with each phosphorus fertilizer.

After harvesting, the plants were tested for dry weight, phosphorusconcentration and phosphorus uptake. SAS was utilized to analyzevariance of the data.

TABLE 4 Phosphorus Materials Evaluation-Corn Material Dry Wt. (g) P.Concentration (%) P Uptake Control 5.18 0.827 43.2 P1X 8.90 0.996 88.7P2X 9.55 1.043 99.6 LSD_(.05) 2.47 0.177 31.8

EXAMPLE 24

In this test, the effects of polymers on nitrogen volitilization wastested. A urea was sized by screening to a uniform size and was treatedto form a 5% by weight coating of a polymer in accordance with thepresent invention. The coating was prepared by solubilizing 5 grams ofpolymer in 3 ml of water. The mixture was then added uniformly to 95 gof urea. To the mixture, 7 g of clay was added which dried the mixtureand provided a clay coating. The mixture was then applied to soil forcomparison. There were two polymers tested, one which was 50% calciumand 50% hydrogen saturated and the other which was 100% calciumsaturated. Each of these polymer mixtures were compared to an untreatedurea. Soil samples were taken and cumulative nitrogen losses weredetermined after 16 days.

As shown in Table 5, coating the urea with clay or a polymer and claycombination greatly reduced nitrogen volatilization. Untreated urea lost37.4% of its total nitrogen. The polymers, calcium/hydrogen mixtures andcalcium alone, lost only 20.6% and 19.5% respectively. Unexpectedly, thepolymer combination significantly reduced nitrogen volatilization.

TABLE 5 Ammonia Loss as a Percentage of Total Nitrogen Applied ReplicateReplicate Replicate Treatment 1 2 3 Average Urea 33.3 41.3 37.7 37.4Urea/Clay/5% Polymer 19.0 19.3 23.7 20.6 50% H, 50% Ca saturatedUrea/Clay/5% Polymer 17.1 21.7 19.5 19.5 100% Ca saturated

EXAMPLE 25

This experiment determined the effects of polymers in accordance withthe invention on phosphorus fertilizer availability. An acid soil (pH4.7) and a calcareous soil (pH 7.8) treated as in Example 23 werecollected. These soils were chosen for their P fixing characteristics,preformed by Fe and Al in the acid soil and Ca in the calcareous soil.All treatments involved four replication. Soil samples were collectedfrom the area of banded P beside the corn row after the plants had beenharvested. The phoshporus material was MAP (although it is understoodthat all fertilizers should have similar results) with and without anexperimental coating of 1.0% on the exterior of the MAP particles. Thecoating was prepared using the procedures described above in Example 24.Phosphorus rates were 5, 10 and 20 ppm P205 banded beside the seed (1inch to the side, 1 inch below) of corn in flats containing 7 kilogramsof soil. Composited cores from each treatment were processed andanalyzed using conventional testing procedures. A single weak acidextractant (Bray P-1) was utilized for both the acid and calcareoussoils. The P fertilizer had been in contact with the soil forapproximately 5 weeks at the time of sampling.

Results of this experiment are given below in Table 6. Coating MAP withthe experimental product produced consistently higher soil test P valuesindicating that the extractability of the P was increased. Therefore,normal soil P fixation had not progressed as rapidly in the presence ofthe polymer. The results from the acid soil displayed moredifferentiation that those of the calcareous soil, perhaps due to thetendency of the weak Bray extractant to react with free calciumcarbonate in the calcareous soil. Plant growth data also demonstratedsimilar indications of greater P availability.

Thus, polymers in accordance with the present invention have significanteffects on P availability from ammonium phosphate fertilizers.Furthermore, these polymers may be of substantial value in improving Puse efficiency from applied fertilizers on both acid and calcareoussoils with P fixation capacities.

TABLE 6 Polymer Effects on Soil Test P Soil Bray-1 P ConcentrationsTreatment ppm P No P Control, Acid Soil 76 5 ppm P205, MAP Control, AcidSoil 121 10 ppm P205, MAP Control, Acid Soil 117 20 ppm P205, MAPControl, Acid Soil 151 5 ppm P205, MAP Experimental, Acid Soil 195 10ppm P205, MAP Experimental, Acid Soil 190 20 ppm P205, MAP Experimental,Acid Soil 220 LSD 0.10, Acid Soil 26 No P Control, Calcareous Soil 76 5ppm P205, MAP Control, Calcareous Soil 96 10 ppm P205, MAP Control,Calcareous Soil 110 20 ppm P205, MAP Control, Calcareous Soil 156 5 ppmP205, MAP Experimental, Calcareous Soil 164 10 ppm P205, MAPExperimental, Calcareous Soil 159 20 ppm P205, MAP Experimental,Calcareous Soil 102 LSD 0.10 Calcareous Soil 38

We claim:
 1. A method of forming a polymer comprising the steps of:providing a reaction mixture comprising at least two different reactantsselected from the group consisting of first, second, and thirdreactants, wherein said first reactant is of the general formula

said second reactant is of the general formula

and said third reactant is of the general formula

wherein R₁, R₂ and R₇ are individually and respectively selected fromthe group consisting of H, OH, C₁-C₃₀ straight, branched chain andcyclic alkyl or aryl groups, C₁-C₃₀ straight, branched chain and cyclicalkyl or aryl C₁-C₃₀ based ester groups, R′CO₂ groups, and OR′ groups,wherein R′ is selected from the group consisting of C₁-C₃₀ straight,branched chain and cyclic alkyl or aryl groups; R₃ and R₄ areindividually and respectively selected from the group consisting of H,C₁-C₃₀ straight, branched chain and cyclic alkyl or aryl groups; R₅, R₆,R₁₀ and R₁₁ are individually and respectively selected from the groupconsisting of H, the alkali metals, NH₄ and the C₁-C₄ alkyl ammoniumgroups, Y is selected from the group consisting of Fe, Mn, Mg, Zn, Cu,Ni, Co, Mo, V, Cr, Si, B, and Ca; R₈ and R₉ are individually andrespectively selected from the group consisting of nothing, CH₂, C₂H₄,and C₃H₆, at least one of said R₁, R₂, R₃ and R₄ is OH where saidpolymeric subunits are made up of A and B moieties, at least one of saidR₁, R₂ and R₇ is OH where said polymeric subunits are made up of A and Cmoieties, and at least one of said R₁, R₂, R₃, R₄ and R₇ is OH wheresaid polymeric subunits are made up of A, B and C moieties; polymerizingsaid reaction mixture to form a polymer having recurring polymericsubunits therein with carboxyl-containing groups; and hydrolyzing saidpolymer to replace at least certain of said ester-containing groups withalcohol groups.
 2. The method of claim 1, said first reactant beingvinyl acetate and said second reactant being maleic anhydride.
 3. Themethod of claim 1, said polymerization step being carried out bygenerating free radicals in said reaction mixture.
 4. The method ofclaim 3, said free radical generation step comprising the step of addinga peroxide to said reaction mixture.
 5. The method of claim 3, said freeradical generation step comprising the step of subjecting said reactionmixture to UV light.
 6. The method of claim 1 said reaction mixturebeing formed in a solvent selected from the group consisting of waterand acetone.
 7. The method of claim 1 said polymerization step beingcarried out at a temperature of from about 0° C. to about 120° C. for aperiod of from about 0.25 hours to about 24 hours.
 8. The method ofclaim 1, said polymerization step being carried out under an inert gasatmosphere.
 9. The method of claim 1, said hydrolyzing step comprisingthe step of adding an acid or base to said polymer.
 10. The method ofclaim 9, including the step of adding a base to said polymer.
 11. Themethod of claim 1, including the step of drying said hydrolyzed polymerto a solid form.
 12. The method of claim 1, including the step ofconcentrating the aqueous solution of the polymer until the polymerprecipitates out.
 13. The method of claim 1, including the step ofreacting said hydrolyzed polymer with an ion to form a complex with thepolymer.
 14. The method of claim 13 said ion being selected from thegroup consisting of Fe, Zn, Cu, Mn, Mg, Mo, Co, Ni, Al, V, Cr, Si, B, orCa ion.
 15. The method of claim 1, said hydrolyzing step being carriedout in situ.
 16. A method of forming a polymer comprising the steps of:providing an aqueous solution of caustic; providing a reaction mixturecomprising at least two different reactants in a solvent, said reactantsbeing selected from the group consisting of first, second, and thirdreactants, wherein said first reactant is of the general formula

said second reactant is of the general formula

and said third reactant is of the general formula

wherein R₁, R₂ and R₇ are individually and respectively selected fromthe group consisting of H, OH, C₁-C₃₀ straight, branched chain andcyclic alkyl or aryl groups, C₁-C₃₀ straight, branched chain and cyclicalkyl or aryl C₁-C₃₀ based ester groups, R′CO₂ groups, and OR′ groups,wherein R′ is selected from the group consisting of C₁-C₃₀ straight,branched chain and cyclic alkyl or aryl groups; R₃ and R₄ areindividually and respectively selected from the group consisting of H,C₁-C₃₀ straight, branched chain and cyclic alkyl or aryl groups; R₅, R₆,R₁₀ and R₁₁ are individually and respectively selected from the groupconsisting of H, the alkali metals, NH₄ and the C₁-C₄ alkyl ammoniumgroups, Y is selected from the group consisting of Fe, Mn, Mg, Zn, Cu,Ni, Co, Mo, V, Cr, Si, B, and Ca; R₈ and R₉ are individually andrespectively selected from the group consisting of nothing, CH₂, C₂H₄,and C₃H₆, at least one of said R₁, R₂, R₃ and R₄ is OH where saidpolymeric subunits are made up of A and B moieties, at least one of saidR₁, R₂ and R₇ is OH where said polymeric subunits are made up of A and Cmoieties, and at least one of said R₁, R₂, R₃, R₄ and R₇ is OH wheresaid polymeric subunits are made up of A, B and C moieties; adding asufficient amount of said reaction mixture to said caustic solution inorder to bring the pH of the resulting reaction solution to about 7;polymerizing said reaction mixture to form a polymer having recurringpolymeric subunits therein with carboxyl-containing groups; performingreduced pressure distillation to remove said solvent; hydrolyzing saidpolymer to replace at least certain of said ester-containing groups withalcohol groups; and isolating said polymer.
 17. The method of claim 16,said first reactant being vinyl acetate and said second reactant beingmaleic anhydride.
 18. The method of claim 16, said polymerization stepbeing carried out by generating free radicals in said reaction mixture.19. The method of claim 18, said free radical generation step comprisingthe step of adding a peroxide to said reaction mixture.
 20. The methodof claim 18, said free radical generation step comprising the step ofsubjecting said reaction mixture to UV light.
 21. The method of claim16, said solvent being selected from the group consisting of water andacetone.
 22. The method of claim 16, said polymerization step beingcarried out at a temperature of from about 0° C. to about 120° C. for aperiod of from about 0.25 hours to about 24 hours.
 23. The method ofclaim 16, said polymerization step being carried out under an inert gasatmosphere.
 24. The method of claim 16, said isolation step beingselected from the group consisting of precipitation, spray drying, andsimple drying.
 25. The method of claim 16, including the step ofconcentrating the aqueous solution of the polymer until the polymerprecipitates out.
 26. A method of forming a polymer comprising the stepsof: providing a reaction mixture comprising at least two differentreactants selected from the group consisting of first, second, and thirdreactants, wherein said first reactant is of the general formula

said second reactant is of the general formula

and said third reactant is of the general formula

wherein R₁, R₂ and R₇ are individually and respectively selected fromthe group consisting of H, OH, C₁-C₃₀ straight, branched chain andcyclic alkyl or aryl groups, C₁-C₃₀ straight, branched chain and cyclicalkyl or aryl C₁-C₃₀ based ester groups, R′CO₂ groups, and OR′ groups,wherein R′ is selected from the group consisting of C₁-C₃₀ straight,branched chain and cyclic alkyl or aryl groups; R₃ and R₄ areindividually and respectively selected from the group consisting of H,C₁-C₃₀ straight, branched chain and cyclic alkyl or aryl groups; R₅, R₆,R₁₀ and R₁₁ are individually and respectively selected from the groupconsisting of H, the alkali metals, NH₄ and the C₁-C₄ alkyl ammoniumgroups, Y is selected from the group consisting of Fe, Mn, Mg, Zn, Cu,Ni, Co, Mo, V, Cr, Si, B, and Ca; R₈ and R₉ are individually andrespectively selected from the group consisting of nothing, CH₂, C₂H₄,and C₃H₆, at least one of said R₁, R₂, R₃ and R₄ is OH where saidpolymeric subunits are made up of A and B moieties, at least one of saidR₁, R₂ and R₇ is OH where said polymeric subunits are made up of A and Cmoieties, and at least one of said R₁, R₂, R₃, R₄ and R₇ is OH wheresaid polymeric subunits are made up of A, B and C moieties; polymerizingsaid reaction mixture to form a polymer having recurring polymericsubunits therein with carboxyl-containing groups; and hydrolyzing saidpolymer to replace at least certain of said ester-containing groups withalcohol groups.
 27. A method of forming a polymer comprising the stepsof: providing an aqueous solution of caustic; providing a reactionmixture comprising at least two different reactants in a solvent, saidreactants being selected from the group consisting of first, second, andthird reactants, wherein said first reactant is of the general formula

said second reactant is of the general formula

and said third reactant is of the general formula

wherein R₁, R₂ and R₇ are individually and respectively selected fromthe group consisting of H, OH, C₁-C₃₀ straight, branched chain andcyclic alkyl or aryl groups, C₁-C₃₀ straight, branched chain and cyclicalkyl or aryl C₁-C₃₀ based ester groups, R′CO₂ groups, and OR′ groups,wherein R′ is selected from the group consisting of C₁-C₃₀ straight,branched chain and cyclic alkyl or aryl groups; R₃ and R₄ areindividually and respectively selected from the group consisting of H,C₁-C₃₀ straight, branched chain and cyclic alkyl or aryl groups; R₅, R₆,R₁₀ and R₁₁ are individually and respectively selected from the groupconsisting of H, the alkali metals, NH₄ and the C₁-C₄ alkyl ammoniumgroups, Y is selected from the group consisting of Fe, Mn, Mg, Zn, Cu,Ni, Co, Mo, V, Cr, Si, B, and Ca; R₈ and R₉ are individually andrespectively selected from the group consisting of nothing, CH₂, C₂H₄,and C₃H₆, at least one of said R₁, R₂, R₃ and R₄ is OH where saidpolymeric subunits are made up of A and B moieties, at least one of saidR₁, R₂ and R₇ is OH where said polymeric subunits are made up of A and Cmoieties, and at least one of said R₁, R₂, R₃, R₄ and R₇ is OH wheresaid polymeric subunits are made up of A, B and C moieties; adding asufficient amount of said reaction mixture to said caustic solution inorder to bring the pH of the resulting reaction solution to about 7;polymerizing said reaction mixture to form a polymer having recurringpolymeric subunits therein with carboxyl-containing groups; performingreduced pressure distillation to remove said solvent; and isolating saidpolymer.